Japanese Rules

Currently the EGF uses the Japanese 1989 Rules if Japanese rules are said to be used.

Japanese rules are the most complex. They are still incomplete but RobertJasiek is doing research that is going to explain them completely in theory (watch for announcements). In practice, the 1 x 2 board might be the biggest board on that Japanese rules can be applied completely. For bigger boards application always means "extremely rough approximation". Then what is an approximation? Until the Japanese 2003 Rules will be published, the 1997 commentary provides useful hints. If that is too advanced for your taste, then look at the following overview:

• Currently the even game komi is 6.5.
• Alternation is followed by game ending phases.
• During alternation a basic ko rule, long cycle rules, and no suicide apply.
• Alternation stops with the pass that succeeds a pass.
• The game ending phases consist of confirmation, analysis, removals, counting, result agreement, and further adventures.
• Dame and teire may but need not be occupied. If they are occupied, then they have to be occupied alternately. Not filling them (except for self-ataris in sekis) is at each player's own risk. He increases the risk in the following order: 1) Not filling during alternation, 2) not filling also during confirmation, 3) filling during analysis after confirmation. The risk is an unfavourable arbitration. (3) is prohibited by the rules. The rules are unclear whether (2) is possible. To summarize, the earlier dame and teire are filled, the lower the risk of an unfavourable arbitration is. In lightning games the risk increases naturally.
• The rules leave it unclear whether or inhowfar confirmation, analysis, removals, counting, result agreement, or further adventures are competitive or may not be competitive. Arbitrary arbitration is a natural consequence.
• The rules leave it unclear whether, how, or inhowfar status questions are determined. The following major theories persist: 1) Status may be determined during confirmation only. 2) Status may be determined only during analysis after confirmation. 3) Status may be determined during confirmation and again during analysis. Additionally there are the following theories: A) The players' agreement has to agree with the rules' "definitions", B) the players' agreement need not agree with the rules' "definitions". Arbitrary arbitration is a consequence.
• The rules do not make it very clear exactly how confirmation is ended and thereby analysis is started. (Analysis is needed so that the players know the status that enable them to remove some particular stones and to score some particular intersections.)
• Counting determines the score mechanically. Essentially, the score refers to one's own empty intersections and prisoners of opposing colour.

Needless to say, the most urgently the EGF needs much clearer rules about Japanese game ending phases. E.g., these could be made similar to those of the Simplified Ing Rules. Until then everything remains unclear.

RobertJasiek 2003-11-01

The Japanese 1989 Rules as Used by the EGF

[Due to tournament rules of the EGF, the tournament rules are cancelled from the text of the Japanese 1989 Rules since those tournament rules do not apply. Besides an EGF tournament rule requires all stones to be played alternately and the EGF Rules and Ratings Commission has agreed to use the Game End Module for the Japanese 1989 Rules. The changes are applied to the English translation of the Japanese 1989 Rules by James Davies, but neither the translation nor the actual application of the changes to it is confirmed by the EGF or the EGF Rules and Ratings Commission yet. Therefore the following must be treated with care. Furthermore, especially §§ 6, 7, 8 are known to be particularly equivocal.]

§1. The game of go

Go is a game in which two players play? on a board, from the beginning of the game until alternate moving? stops [according to §A1...]

§2. Play

The players can alternately play one move at a time, one player playing the black stones, his opponent the white stones.

§3. Point of play

The board is a grid of 19 horizontal and 19 vertical lines forming 361 intersections. A stone can be played on any unoccupied intersection (called an "empty point") on which §4 permits it to exist. The point on which a stone is played is called its "point of play."

§4. Stones that may exist on the board

After a move is completed, a group of one or more stones belonging to one player exists on its points of play on the board as long as it has a horizontally or vertically adjacent empty point, called a "liberty." No group of stones without a liberty can exist on the board.

§5. Capture

If, due to a player's move, one or more of his opponent's stones cannot exist on the board according to the preceding article, the player must remove all these opposing stones, which are called "prisoners." In this case, the move is completed when the stones have been removed.

§6. Ko

A shape in which the players can alternately capture and recapture one opposing stone is called a "ko." A player whose stone has been captured in a ko cannot recapture in that ko on the next move.

§7. Life and death

1. Stones are said to be "alive" if they cannot be captured by the opponent, or if capturing them would enable a new stone to be played that the opponent could not capture. Stones which are not alive are said to be "dead." 2. In the confirmation of life and death after the game stops in Article 9, recapturing in the same ko is prohibited. A player whose stone has been captured in a ko may, however, capture in that ko again after passing once for that particular ko capture.

§8. Territory

Empty points surrounded by the live stones of just one player are called "eye points." Other empty points are called "dame." Stones which are alive but possess dame are said to be in "seki." Eye points surrounded by stones that are alive but not in seki are called "territory," each eye point counting as one point of territory. [...]

§12. No result

When the same whole-board position is repeated during a game, if the players agree, the game ends without result. [...]

Appendix: EGF Game End Module

§A1. Alternate moving stops with two successive passes.

§A2. Then the players

1. continue alternate moving to occupy those dame and teire that are still unoccupied and that they want to occupy,
2. determine the alive and dead stones and territory,
3. remove the dead stones from territory,
4. count the scores to determine the result,
5. make the result agreement.

§A3. If the players disagree after alternate moving stops and before the result agreement, then alternate moving continues from the state of the last stop as if nothing had happened thereafter. However, a referee may prescribe the players' actions.]

RobertJasiek 2004-02-22